New leukaemia cluster in Chepstow

Cluster of Childhood Leukaemia and Cancer
in Chepstow similar to Seascale

Low Level Radiation Campaign Press release 29th April 2001: Immediate use.

A report "Cancer Mortality and Proximity to Oldbury Nuclear Power Station in Gloucestershire 1995-1999" was commissioned from consultants Green Audit by Michael Holmes MEP.

In connection with the cancer mortality study an analysis of childhood leukaemia and cancer incidence in Chepstow has also been conducted. It has been made possible by the release, in 1995, of Wales Cancer Registry's entire database of cancer incidence at local authority ward level to the Low Level Radiation Campaign. Cancer incidence data are usually only published in a highly aggregated form, at the level of counties or county districts.

Both reports can be downloaded as Word files from this web site ( together with coloured maps of cancer mortality risk ward by ward. (see links at foot of page)
This material can also be can be sent by email. Contact Richard Bramhall if necessary.

The leukaemia cluster in Chepstow is statistically significant. It is similar in intensity to the notorious Seascale cluster although direct comparison is not straightforward. In Chepstow between 1974 and 1990 (17 years) at least 4 cases were diagnosed in children younger than 5 years - 2.4 times the expected number (1.68). Three of them were the rare Myeloid form of leukaemia - more than 11 times the expected number (0.27). The presence of this disease is strongly suggestive of a radiation link. (in Chepstow UD Relative Risks are even higher and are still statistically significant; the fact that large parts of Chepstow RD are distant from the Severn may account for their lower risks)
Relative Risks of childhood cancer in Chepstow show a pattern similar to the leukaemia risks.

In Seascale between 1968 and 1995 (28 yrs (note 1) 3 leukaemias were diagnosed in children younger than 5 years; 6 were diagnosed in those under 14 years. For the 0 - 14s this is 12.3 times the expected number (expected rates for the 0 - 4s are not available)
In addition it is reported from Chepstow that as many as four cases have been traced which may not be on the files analysed for this study. If true this has serious implications concerning earlier analyses of the Wales Cancer Registry databases which will reopen discussion between this Campaign and COMARE. This issue will not be addressed in this press release.

The Seascale cluster has persisted for over 30 years. It was discovered by Yorkshire TV and hit the headlines in the mid '80s in a programme called Windscale: the Nuclear Laundry. This led to the Black Committee, whose report recommended that the Government set up the Committee on Medical Aspects of Radiation in the Environment (COMARE) and the Small Area Health Statistics Unit (SAHSU). SAHSU was set up to ensure that in future clusters of disease would be discovered by official agencies rather than by reporters and campaigners (see They have instead concentrated on developing and propagating methods of dismissing clusters as random occurrences. Their current study of cancer around the Bradwell nuclear power station employs a crude method which makes no attempt to follow the distribution of radioactivity in the local environment and seems to have been designed deliberately to find no effect.

COMARE has uncritically accepted the National Radiological Protection Board's recommendations despite the demonstrable weakness of the NRPB model of radiation risk at environmental levels of dose. Accordingly COMARE has found that radioactivity from Sellafield could not be the cause of the Seascale cluster. Clear bias in COMARE's approach to reports of high cancer risk in parts of Wales near radioactively contaminated mud banks is evident in Minutes leaked to LLRC (see

It is clear that COMARE and SAHSU are failing in their jobs and LLRC is calling for them both to be replaced.

Cancer Mortality Study: Background

Cancer mortality between 1995 - 1999 (Note 2) has been analysed at the level of local authority wards in the area potentially affected by discharges of radioactivity into the Severn Estuary from three nuclear power stations and Nycomed Amersham plc's Cardiff site. It is believed that this is the greatest concentration of such nuclear pollution anywhere in the world. Strong tidal action carries the radioactivity up and down the estuary. In addition the Severn and the Wye drain a large part of the Welsh uplands, and are therefore transporting radioactive fallout into the same area. This fallout came from atmospheric testing of nuclear bombs on the 1950s and '60s and from Chernobyl. Wet regions such as Wales receive more fallout than dry areas, in proportion to rainfall.

There is a large amount of evidence suggesting that cancer rates are associated with radioactive contamination of mud in estuaries.
Monitoring of mud in the Severn has been conducted by MAFF, showing 70 nanoGrays per hour (nGy/hr) of gamma rays. This is more than double the inland radiation rate measured by NRPB (30 nGy/hr).
MAFF monitoring of tritium in surface water of the Severn shows that concentrations increase upstream.
Fine particles of contaminated silt are easily resuspended in air and inhaled. Such particles have been detected many miles inland.

Main conclusions of the cancer mortality study

  • Wards near nuclear power stations do not have high risks, except for prostate cancer. The high risks are mostly below the Severn Bridge, in Woodspring, south Avon and the Welsh coast.
  • The coastal effect observed in other parts of the country is present; risk for all cancers increases with proximity to the coast; the trends have very high statistical significance, except in the case of prostate cancer.
  • Lung and breast cancer risks are strongly associated with living in the valleys of the rivers Wye, Avon and Frome, particularly Chepstow at the mouth of the Wye. This suggests that smoking has less to do with lung cancer than environmental factors where people live. The Gordano valley (which has no river) has high risks for all cancers.
These findings support the hypothesis that risk is positively associated with residence near areas of radioactively contaminated mud and that the radioactivity is a major factor in causing the cancers. Other factors, such as pollution from petro- chemical works, probably contribute to risks. It is well recognised that factors interact and multiply risks.


  • COMARE and SAHSU should be replaced.
  • Localised cancer incidence data for England, plus recent Welsh data, should be released to responsible independent research organisations for the purpose of environmental studies of associations between localised contamination and variations in disease rates
  • Scientific models of radiation risk at low dose and dose rate must be thoroughly reviewed.


    • Dr Busby (Green Audit) 01970 639 315 / 07989 428833
    • Richard Bramhall (Low Level Radiation Campaign) 01597 824771
    • Jim Duffy (Stop Hinkley) 07968 974 805

    1 i.e. the period covered by the 4th Report of COMARE
    2 these data are available for purchase from the Office of National Statistics, in contrast to incidence data, which Cancer Registries refuse to release. Incidence data are far more informative, due to the larger numbers and the fact that the influence of environmental factors tends to be masked by people moving house between diagnosis and death (Incidence data are usually coded to residence at diagnosis)

    Note 3 "SMR" = Standardised Mortality Ratio - the rate of deaths relative to national average rates after adjustments have been made for the age structure and relative social status (or deprivation) of the study population. For example 1.31 means "1.31 times what you would expect on the basis of national averages for a (hypothetical) population with the same proportions of people aged 0 - 4 years, 5 - 9 years, and so on, and where the people have the same income levels, types of job, standards of housing, diet, smoking habits and so on as the area in the study." You could also call it "31% above average".

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This page was last updated May 2001